Electron valve with subdivision of the system supports affording heat protection



Oct. 24, 1933. ROMHILD ELECTRON VALVE WITH SUBDIVISION OF THE SYSTEMSUPPORTS AFFOHDING HEAT PROTECTION Filed Aug. 25, 1928 Patented Oct. 24,1933.

ELECTRON VALVE WITH; SUBDIVISION or I THE SYSTEM SUPPORTS- AFFORDING IHEAT PROTECTION Edgar-Riimhild, Berlin, Germany I Application August 25,1928, Serial No. 301,966, r and in Germany August 31, 1927 Claims. (01.250-275) In electron valves the leads to the different electrodesarranged within a valve or the leads to the different electrodes formingpart of one system of electrodes are generally held in the desiredposition by passingthem through an insulation piece which may consist ofa small glass rod-,- the different conductive leads thus being arranged(fused) in close proximity with one another in a uniform insulationcompound.

0 Generally insulation pieces are made of such material as glassetc.which at normal room temperature affords suchgood insulation thatdisturbing current transitions from one electrode to other ones areavoided. It has however been found that the cathode being heated to theoperation temperature, oftensuch a lot of heat is developed that theglass rod is heated to a rather high temperature of about 250 to 400degrees. The insulation power of the glass at this temperature beingessentially. diminished, disturb- I ances are produced by leakagecurrents between the single leads. These kinds of disturbances ought tobe particularly avoided becausethey are causing a detrimental variationof the value of the grid potential. 'Said variation of the gridpotential, being able to disturb wholly the good working the valve,especially if the electrode systems concerned are connected to form aresistance coupled amplifier. It has been proposed .to arrange insidethe glass,

supports between the leads special protecting electrodes which areconnected with an auxiliary potential which is nearly as large as thepotential of that lead which shall be protected. i An object of myinvention is an electron valve in which the glass support is subdividedin such manner as to prevent leakage currents between the single leads.

A further object of my invention is to provide several supports for thedifferent leads, said supports being or being notjoined witheach otherby means ofauxiliary glass rods, wires or the like. w

A still further object of my invention is to pro another support for theanode and the grid leads.

.Stillfurther objects of my invention will be best understood withreference to the description and the drawing. v

Referring to the accompanying drawing Fig. 1 is a perspective view of anelectron. valve in which according tothe invention two glass rods areprovided, and the electrode system of which contains a directlyheatedincandescent cathode.

' Fig. 2, and

vide one support for the cathode leads and.

- Fig.2 is a side elevational view of a valve, which essentially.corresponds with the valve shown in Fig. 1, the electron system of whichcontains yet an indirectly heated cathode. r 1 V Fig. 3 is anelevational view of a valve in which the glass support is subdividedaccording to' the so invention in three independent parts.

Fig. 4 is a plane view taken on line C-C in Fig. -2.

Fig. 5 is a plane view taken on line BB in I Fig. 6 is a plane viewtaken on line A-A in 1 is the anode which, for instance, may have, theform of a cylinder and may be provided with a sheet edge 2 to which twowire supports 3 and 4 are attached the terminals of which are jointlyheld in the glass rod 5. The wire 3 thusmerely serves'for fasteningwhile the wire 4 serves as the lead of-the plate. voltage. Thecontrolelectrode (thegrid) '6 is held by the wire supports '7 and 8, 1

ct which '7 in its turn serves merely as a mechanical support while 8serves as the lead of the grid voltage. The four wires 3, 4, 7 and 8 areheld'in the glass rod 5. Below the rod 5 there is a further rod 9 insideof which the two leads 10 and 11 are fastened-1 .which carry theincandescent cathode "12 and. which serve at the same time as leads ofthe heating current.

m the arrangement according to Fig. l the glass rod 9 is subjected tofairly considerable heating especially in the spots close to the. wires10 and 11. The resistance, which still has a value ofmany ohmsproduces'an inconsiderable currentloss between the two seals 10 and 11.On the other handa voltage arises between the wires 3 and 4 connectedwith the anode and between the wires 7, and 8 connected with the gridand likewise inside rod 5. The excellent insulation which is absolutelynecessary between these electrodes and which would already fail if thecontact resistance would sink to an amount of several megohms, is in thearrangement described jeopardized in no respect, since the temperatureof the glassrod 5 remains much below the temperature at which anoticeable conductive increase 100 may take place, the incandescent wireconducting its heat not to thisglass rod 5, but to theother glass rod9'. In Fig. 2 is shown in what manner the arrangement according to Fig.1 may be supplementedfor obtaining an indirectly heated cathode: thecathode 13 which may be constructed as a thin tube surrounding theheater, is connected by means of the wires 14 and 15 with the glassrodi). These wire leads, as is not particularly shown in Figure .2, arerun outside the. supply area in order to avoid the exertion of aninfluence by the leads to the other electrodes. Wire 14 again ends atthe glass stick 9 while wire 15 serves as the cathode lead.

If the two glass beads 5 and 9 of Fig. 1 are not sufficiently stable itmay be advisable to use additional supporting wires 16 and 17 I In thecase of multiple valves several electrode systems according to myinvention may according to Fig. l be arranged inside one valve when itis not always necessary for all electrode systems to be constructed. Invalves withseveral voltage amplification stages and one poweramplification stage it may be advisable on the contrary, to protect moreparticularly the voltage amplification stages, which are especiallysensitive to insulation disturbances, in the manner described andillustrated in Figs. 1 and 2.

Fig. 3 discloses a further embodiment of my invention in which the leadin wires to the indirectly heated cathode are supported by. a particularglass rod. Besides glass rod 5 for anode and grid and the glass rod 9merely supporting the heating wire, a special glass rod 18 is providedwhich supports the cathode bilaterally and which by wires 19, and 20 ismechanically con nected withthe rod 9. 22 is the flare tube of the valvethrough which the wires 4, 8, 10, 11, and 15 are passed to the outside.

My invention is not limited to the embodiments as shown in the figures.Whilst hitherto for every single electrode system there was merely asimple undivided and generally cylindrically constructed support, thesupport according to my invention is subdivided in any manner in orderto protect the parts which are sensitive to insulation damages, againstleakage currents. With multiple valves my invention may also be carriedout in such manner that several electrically or therrnotechnicallyequivalent leads of diiierent electrode systems are held at one support:for instance the incandescent wires of two voltage amplifying electrodesystems may be supported by one mutual pedestal.

I claim:

1. An electron discharge device comprising an evacuated vessel, a stem,an electrode system consisting of a plate, a grid and an electronemitting source, current supply-wires passed through said stem to saidelectrodes, support-wires for said electrodes, a supplemental insulationsupport-member supporting the current-supplywires and the support-wiresfor said anode and grid, and a second insulation-support-membersupporting the current-supply-wires for said electron emitting source.

2. An electron discharge device comprising an evacuated vessel, a stem,an electrode system consisting of a plate, a grid and an electronemitting source, current-supply-wires passed through said stem to saidelectrodes, support-wires for said electrodes, one glass rod supportingthe currentsupply-wires and the support-wires for the anode and grid,and another glass rod supporting the current-supply-wires for saidelectron emitting source. v

3. An electron discharge device comprising an evacuated vessel, a stem,an electrode system consisting of a plate, a grid and an electronemitting source, current-supply-wires passed through said stem to'saidelectrodes, support-wires for said electrodes, a supplementalinsulation-supportmember supporting the current-supply-wires and thesupport-wires for the anode and the grid, and a secondinsulation-support-1nember supporting the current-supply-in wires forsaid electron emitting source and additional supportwires connecting andstiffening said insulationand the grid, and another glass rod supportingthe current-supply-wires for said electron emitting source andadditional support-wires connecting and stiffening said glass rodsoneagainst V the other.

5. An electron discharge device comprising an evacuated vessel, a stern,an electrode system consisting of a plate, a grid, a heating filamentand an equipotential cathode insulated from this heating filament,current supply wires passed through said stem to said electrodes,supportwires for said electrodes, a supplementalinsulation-suppcrt-member supporting the currentsupply-wires and thesupport-Wires for the anode and grid, a second insulation-support-membersupporting the current-supply-wires for said heating filament andsupport-wires to support said first insulation-support-member, and athird insulation-support-mernber supporting one pair of support-wiresfor the equipotential-cathode and another pair of support-wiressecuredto said second insulation-support-member.

6. An electron discharge device comprising an evacuated vessel, a stem,an electrode system con sisting of a plate, a grid, a heatingfilamentand an equipotential cathode insulated from this heating filament,current supply wires passed through said stem to said electrodes,supportwires for said electrodes, a supplemental insula- 1L5tion-support-member supporting the currentsupply-wires and thesupport-wires for the anode and grid, a second insulation-support-membersupporting the current-supply-wires for said heating filament, a thirdinsulation-support member supporting the anode current-supplywire andadditional-support-wires connecting and stiffening saidinsulation-support-members oneagainst the other.

7. An electron discharge device comprising an evacuated vessel, a stem,an electrode system consisting of a plate, a grid, a heating filamentand an equipotential cathode insulated from this heating filament,current supply-wires passed through said stem to said electrodes,support- LAG an equipotential cathode insulated from this heatingfilament, current-supply-wires passed through said stem to saidelectrodes, supportwfres for said electrodes, one glass rod supportingthe cUrrent-supply-Wires and the supportwires for the anode and grid, asecond glass rod supporting the current-supply-wires for said heatingfilament, a third glass rod supporting the anode current supply Wire andadditional150 9. An electron discharge device comprising an.

evacuated vessel, a stem having a press portion, grid plate andfilament, an insulation-supportmember and acomplemental-insulation-supportmember, one pair offilament-current-supplywires secured to said press and to saidinsulatingsupport-member supportingsaid insulation-support-member, meansto secure said filament to the said pair offilament-current-supply-wires, one pair of support-wires secured to saidinsulation-support member and to saidcomplementalinsulation-support-member and means to secure saidsupport-Wire to one end of said grid,'to support said grid, onegrid-voltage-supply-wire secured to said press and to saidcomplemental-insulation-support-member and means to secure saidgrid-voltage-supply-wire to the other end of said grid to supportthisother end of the grid, one support-Wire secured to saidcomplementalinsulation-support-member and means to secure saidsupport-wire to one point of said plate to support the plate, and aplate-current-supply- Wire secured to said press and to said comple-'mental-insulation-support-member and means to securesaid.plate-current-supply-wire to another point of said plate.

10. An electron discharge device comprising an evacuated vessel, a stem,having a press portion, grid, plate and filament, a glass rod and asecond glass rod; one pair of filament-current-supplywires secured tosaid press and to said second glass rod supporting said first glass rod,means to secure said filament to the said pair offilamentcurrent-support-wires, one pair of support-wiressecured to saidfirst glass rod and to said second glass rod and means to secure saidsupport-wire to one end or" said grid, to support said grid, onegrid-voltage-supply-wire secured to said press and to said second glassrod and means to secure said grid-voltage-supply-Wire to the other endof said grid to support this other end of the grid, one support-Wiresecured to said second glass rod andrmeans to secure said'support-Wireto one point of said plate to support the plate, and aplate-current-supply-Wire secured to said press and to said second glassrod and means to secure said plate-current-supply wire to another pointof said plate. V

- EDGAR ROMHILD.

